Hi all,
I use an MC6 Pro to send MIDI to the MetaModule. Everything works great, except for a high-pitched ground loop noise that appears as soon as I connect the two devices.
I wonder if this is happening because the MM (host) is powering the MC6 Pro. I noticed that the noise increases significantly if I disconnect the external 9V power supply from the MC6 Pro.
Is there a way to turn off power output from the MetaModule’s USB-C port? Alternatively, can anyone recommend a USB noise isolator/filter to insert between the two devices?
usb (host) does not supply power if the device doesn’t request it, which it wont if connected to the mains.
ground loops only occur if 2+ devices are connected to mains (that’s the loop), so should not occur if you do not use external power. (unless, you have other devices attached to the mains)
the other noise polluter, would be switching noise… that occurs regardless of power.
does the usb cable you use have a ferrite choke (or 2) on it?
this helps for switching noise (but not ground loops)
any good quality USB cable with chokes would be good,
(you can also add ‘external’ chokes to a cable)
Hi, thanks for clarifying… I suspect it might be switching noise, especially because it’s a subtle squeal with no low-end noise.
My cable is quite good, but I’ll try adding some ferrite chokes and let you know! 
Thanx!
Hi all,
connecting in new Device Mode (with the new firmware, midi coming from midi host port on the MC6pro) noise is gone! 
The strange thing is that in that way only one kind of CC messages is not sent. It’s a CC waveform generator sent by the MC6 pro. I use it to make a kind of slow rising of one parameter in my MM preset.
If I connect in Host mode the message is perfectly sent… in Device mode the message is not sent 
Any idea??
